Waste heat economizer



1935. P. w. KAISER WASTE HEAT ECONOMIZER Filed Sept. 7. 1954 2 Sheets-Sheet 1 filmmm UMN Q U M W U W W W W H W i M E m INVENTQR Peler W Kalser BY 71. M

ATTORNEY 1935. P. w. KAISER WASTE HEAT ECONOMIZER Filed Sept. '7. 1934 2 Sheets-Sheet 2 INVENTOR Peier W KaLser aha ATTORNEY Patented Nov. 12, 1935 UNITED STATES znzotss PATENT OFFICE 3 Claims.

The present invention relates to waste-heat economizers and is more particularly directed toward economizers adapted for use in connection with domestic heating furnaces for obtaining hot water or hot water and low pressure steam.

It is well known that many furnaces employed for domestic heating are ineflicient in the use of fuel in thata considerable portion of the heat energy available in the fuel is dissipated in the form of hot gases which pass up the chimney. These gases are much hotter than necessary to maintain the requisite draft. Attempts have. been made to improve the eificiency of the furnaces by extending the boiler section or other part of the furnace so as to present more heating surface to hot gases so that the gases are cooled to a lower temperature before they are discharged. The altering of existing installations to secure the increased efiiciency is not always feasible. As a plentiful supply of hot water is always desirable in the home, the present invention contemplates the use of a waste-heat economizer which can take the hot discharge gases from the furnace and utilize the heat energy in the same for heating water. This has been found to be more economical than to attempt to heat the water by coils placed over the fire box or by heat interchanges utilizing the hot water in a low pressure heating boiler.

Other and further objects of the present invention will appear as the description proceeds.

The accompanying drawings show, for purposes of illustrating the present invention, several of the many embodiments in which the invention may take form, it being understood that the drawings are illustrative of the invention rather than limiting the same. In these drawmgs:

Fig. 1 is a vertical sectional view diagrammatically illustrating an economizer of the single pass type.

Fig. 2 is a similar View illustrating a wasteheat economizer of the two pass type; and

Fig. 3 shows an arrangement for securing superheated steam.

In the form of construction shown in Figure 1 a hot Water tank is indicated at I". This tank is annular, having inner cylindrical walls II, outer cylindrical walls I2, top wall I3 and bottom wall I3a, and may be made out of steel suitably welded or riveted together. The duct for receiving the hot discharge gases from the furnace is indicated at I4. It extends into a chamber I5 above the tank I0. As shown at the lower left of Figure 1, the tank is cut back at I6 to passes into the chamber I5 down through the central opening I9 provided by the inner tank walls I I, out through the opening I6, ducts 10 I1 and I8 to the chimney. In order to abstract a maximum amount of heat from the gases they are caused to pass through coils indicated at 20. These coils are made of copper pipe and are connected to the tank Ill as indicated at 2| and 22. 15

' The water supply is indicated at 23 and the hot Water pipe for discharging hot water is indicated at 24. It will be obvious that the gases passing through the economizer will give up their heat energy to the water in the coils 20 and the 20 tank I0 causing the water therein to become hot. The connection of the coils at the top and bottom promotes rotary circulation of the water in the tank Ill.

A by-pass damper 25 is carried at the left 26 of the chamber I5 and this damper is arranged to permit the direct passage of the hot gases from the chamber I5 to the duct I8 without passing them through the economizer. This bypass damper may be manually controlled or au- 30 tomatically controlled by steam pressure or hot water temperature, employing known forms of device for such purpose. A supplemental damper 26 is placed between the exit passage I6 and duct I! as an additional control for the gases. 35 The tank is preferably surrounded by insulating material indicated at 21 and an ornamental covering indicated at 28.

The hot water produced in the economizer may be used for heating or other purposes. used for heating, the economizer is connected in with the remainder of the hot water system.

' In the form of construction shown in Figure 2, the tank Illa is similar to the tank I0 and is provided with coils 20a similar to coils 20. The hot 45 gases are brought in through a pipe I la which connects with the chamber I5a directly over the central opening of tank Illa. This tank is connected to supply pipe 23a and discharge pipe 24a and supported on suitable legs (not shown) so as 50 to be above the floor line. It is received within a drum 3%) concentric with the tank so that the hot gases flow as shown by the arrows, passing down through the coils, then under the bottom of thetank and up outside of the tank where 56 When 40 I they pass into a chimney or flue as indicated at 3!. The by-pass damper 32 corresponds with the damper 25 of Figure 1. V

. The modified form of construction shown in Figure 3, intended for both steam and hot water, may be generally like that shown in either Figure 1 or 2. For convenience, the two-pass arrangement of Figure 2 is selected for illustration, and corresponding parts are indicated by the same reference characters. In this case the tank Illa is provided with a water gage 34 and the water level is intended to be maintained so that it can be read from this gage. The steam space at the top of the tank liia is connected by pipe 35 with a coil 36 placed in the path of the gases so that the steam generated in the tank Illa may be superheated by these gases. The steam is taken off by the pipe indicated at 31 for use.

It is obvious that the invention may be embodiedin many forms and constructions within the scope of the claims, and I wish it to be understood that the particular forms shown are but a few of the many forms. Various modifications and changes being possible, I do not otherwise limit myself in any way with respect thereto.

What is claimed is:

1. A Waste-heat economizer and water heater for operation by hot gases discharged from a furnace, said economizer comprising a double walled vertical water tank of annular cross section to provide an axial opening for passage of gases through the center of the tank, a hot gas supply duct connected with the top of said central opening, a discharge duct outside of and concentric with the tank, and communicating with the bottom of said central opening, a direct connection between the supply duct and the discharge duct, and a damper for opening or closing the direct connection at will so that the gases nection between the supply duct and the discharge duct, anda damper for opening or closing the direct connection at will so that the gases may be directed through the economizer or so that the economizer may be bypassed at will, said economizer having a water heating coil connected at its upper and lower ends to the tank and disposed in the central opening in the path of the gases.

3. A boiler and waste-heat economizer for operation by hot gases discharged from a furnace and comprising a double walled vertical tank of annular cross section to provide an axial opening Q for downward passage of gases through the center thereof, a hot gas supply duct connected with the top of said central opening, a discharge duct communicating with the bottom of said central opening, a direct connection between the supply 5 duct and the discharge duct, a damper for opening or closing the direct connection at will so that the gases may be directed through the economizer or so that the economizer may be bypassed at will, and a steam coil disposed in the upper part of the central opening and in the path of the incoming gases, said coil being connected to the top of the tank to receive steam generated in the tank and superheat this steam.

PETER WILLIAM KAISER. 

